티아졸로벤지미다졸 및 티아디아지노벤지미다졸 유도체의 합성

학위논문(석사) - 한국과학기술원 : 화학과, 1984.2, [ iii, 52 p. ]An improved synthetic method was investigated for some bridgehead nitrogen heterocycles - thiazolo- or thiadiazino-benzimidazoles. 2-Mercaptobenzimidazole(2-benzimidazolethiol) was prepared by the treatment of o-phenylenediamine with carbon disulfide following the method of Van Allan and Deacon. Thiazolo-3,2-a-benzimidazol-3(2H)-one, thiazolo-3,2-a-benzimidazole-2,3-diones, 1,2,4-dithiazolo-3,2-a-benzimidazol-3-one were synthesized using ring closure reaction of 2-benzimidazolethiol with chloroacetyl chloride, oxalyl chloride, chlorocarbonylsulfenyl chloride, respectively. These heterocyclic compounds were obtained in the hot carbon tetrachloride solution as the result of the suspension reaction without the hydrochloric acid trapping agents. 2- {(Alkyl- or Aryl-amino) carbonyl] thio} benzimidazoles were prepared by the treatment of 2-benzimidazolethiol with alkyl- or aryl-isocyanate in pyridine. The ring closure reaction of these carbamates with phosgene and thiophosgene resulted in 1,3,5-thiadiazino-3,2-a-benzimidazole-2,4-diones and their sulfur analogues, respectively. These heterocyclic compounds were obtained in the ether/$Et_3N$ solution and in the carbon tetrachloride solution. Better yields were obtained in the ether/$Et_3N$ solution.한국과학기술원 : 화학과

A study on real-time recognition of two-dimensional objects using interrelation quadruplet

학위논문(박사) - 한국과학기술원 : 전기및전자공학과, 1995.2, [ viii, 134 p. ]한국과학기술원 : 전기및전자공학과

A theory of modified incremental circle transform and its application for recognition of two-dimensional polygonal objects

학위논문(석사) - 한국과학기술원 : 전기 및 전자공학과, 1990.2, [ [ii], 59 p. ]한국과학기술원 : 전기 및 전자공학과

α-티오실란 유도체들의 반응에 관한 연구

학위논문(박사) - 한국과학기술원 : 화학과, 1990.2, [ vii, 126 p. ]Several α-thiosilane deriveatives were synthesized by the reaction of chloro(phenylthio)methyltrimethyl silane with nucleophiles. Nucleophiles employed were Grignard reagents, organoalanes, alcohols, and thiols to give α-alkylated, alkenylated, or alkynylated thiosilanes, α-silyl monothioacetal, and α-silyl dithioacetal, respectively. Chemoselectivity in the Lewis acid promoted reactions of various monothioacetals was investigated through the reaction with several nucleophiles such as phosphites, arenes and alk-1-enes. Monothioacetal of benzaldehyde showed chemoselective phosphorylation by the alternation of the Lewis acid employed, whereas monothioacetal of n-heptanal did not. α-Silyl monothioacetal worked only as α-phenylthiosilylmethyl carbocation equivalent in the Lewis acid mediated reaction with phosphites, arenes, and alk-1-enes. α Phosphoryl monothioacetal showed the same cleavage pattern in the Lewis acid mediated reaction with arenes. The preparation of several functionalized vinyl sulfides was performed. α -Silyl vinyl sulfides was obtained by the reaction of α-thiosilylalkanes with N-chlorosuccinimide via the intermediary α-chloro sulfides without the addition of external base or acid. Employment of two equivalents of NCS gave 1, 2-dichloro-2-phenylthio-2-silylalkanes, which underwent a facile β-elimination of HCL by the treatment with silica to give the corresponding β chloro-α silyl vinyl sulfides. This 1, 2-dichlorinated adducts could also be converted into α-chloro vinyl sulfides by the treatment with potassium fluoride dihydrate in DMSO. α-Cyano vinyl sulfides were prepared using the Peterson olefination method. The Peterson reagent, prepared by the silylation of methylthioacetonitrile using TMSOTf, could be extended to enolizable carbonyl compounds.한국과학기술원 : 화학과